@inproceedings{lee00algorithms,
  author = {Lee, Daniel D. and Seung, H. Sebastian},
  booktitle = {{NIPS}},
  interhash = {cf8707cab8812be3c21d3e5c10fad477},
  intrahash = {a54d0f1fa298d6e6a7135fa56b80fb5e},
  pages = {556-562},
  title = {Algorithms for Non-negative Matrix Factorization},
  url = {/brokenurl#citeseer.ist.psu.edu/lee01algorithms.html},
  year = 2000
}

@article{lee99,
  author = {Lee, Daniel D. and Seung, H. Sebastian},
  interhash = {b293699f3a0541bd6fb1b10d7f9410ac},
  intrahash = {ba1100135fbba9782a6052b95e6f9b05},
  journal = {Nature},
  key = {Lee and Seung},
  pages = {788--791},
  title = {Learning the parts of objects by nonnegative matrix factorization},
  volume = 401,
  year = 1999
}